The stream of civilians fleeing Sri Lanka's war zone picked up speed and air force jets killed 11 guerrillas in a strike that left the leader of the Tamil Tigers' naval wing missing.

The stream of civilians fleeing Sri Lanka's war zone picked up speed and air force jets killed 11 guerrillas in a strike that left the leader of the Tamil Tigers' naval wing missing, the military said on Saturday.

More than 50,000 soldiers are converging on a tiny wedge of jungle in the Indian Ocean island's northeast to crush the Liberation Tigers of Tamil Eelam (LTTE) separatists and end one of Asia's longest-running wars.

With rebel territory fast shrinking, the hunt is on for Tiger leaders including the elusive Vellupillai Prabhakaran, the man who founded the group that turned the suicide bomb into a weapon of war and landed on numerous international terrorism lists.

Initial reports said it may have been a Prabhakaran hideout, but later was found to be an operational base for the LTTE's "Sea Tigers" naval wing and its chief, Soosai, he said.

"Intelligence reports say the whereabouts of Soosai is not known. He is now missing," Nanayakkara said.

Later, jets returned and destroyed a backhoe digging up the bombed site, and another was called afterwards, according to monitored LTTE communications, he said.

"That implies there was a leader. Otherwise they wouldn't dig that place up like that," Nanayakkara said.

US, EU, Canadian and Indian terrorist lists, could not be reached for comment.

The pro-rebel website www.TamilNet.com said late on Friday more than 1,000 soldiers had been killed since Feb 1, and that Tiger commandos had seized an army weapons dump. It quoted unnamed LTTE sources. The military called the report false.

Verifying battlefield reports is next to impossible since the war zone is sealed off to independent media.

CIVILIANS ESCAPE

Trapped inside the 175 square km (67 sq miles) of rebel-held territory are tens of thousands of civilians, whom aid agencies, the government and rights groups say are forcibly being held there by the LTTE. The rebels deny that.

The number of people fleeing has gathered pace this week, and rose sharply on Friday.

According to a military tally, around 10,800 civilians have fled this year 6,600 of those on Thursday and Friday alone. Aid groups say 250,000 are in the war zone. The government says the number is about half of that.

People who escaped on Friday were brought to Kilinochchi, the town the rebels had declared as the capital of the separate state they wanted to create, Nanayakkara said. Troops seized it on Jan 2, first in a string of major victories this year.

They were due to be brought to Vavuniya, a north-central town where the government has major military and humanitarian facilities, Nanayakkara said. A witness in Vavuniya told Reuters that roughly 3,000 people had been brought there since Friday.

Amid growing international outcry over the fate of civilians, the government has reiterated its promise of safe passage, but has refused calls for a truce for negotiations.

The United States, Britain, the European Union and others have urged the Tigers to surrender, and for both sides to stop firing temporarily to allow civilians out and aid in.